In various kinds of organisms, structures having a linkage of disaccharide of N-acetylgalactosamine-N-acetylglucosamine have been found in oligosaccharides of glycoproteins and glycolipids [see References 1 and 2]. In humans, this disaccharide structure is known as a β1-4 linkage (GalNAcβ1-4GlcNAc), and is found only in N-glycans [see Reference 3]. Methods for obtaining human-type oligosaccharides including said structure are limited to methods using complicated chemical synthesis and methods obtaining the oligosaccharides from natural proteins. Further, the above disaccharide structure includes in vivo a galactose substituted for a N-acetylgalactosamine. Therefore, it is a lengthy, laborious process to obtain oligosaccharides having the target disaccharide structure.
Prior to the present application, the inventors identified ppGalNAc-T10, -T11, -T12, -T13, -T14, -T15, -T16, -T17, CSGalNAc-T1, and -T2 as enzymes having an activity of transferring N-acetylgalactosamine to glucuronic acids and polypeptides, and further, they clarified the structures of these genes. Already known are at least 22 N-acetylgalactosamine transferases that have the activity of transferring N-acetylgalactosamine (Table 1), and each of the transferases have different specificities of acceptor substrates.
TABLE 1N-acetylgalactosamine transferase and the substrate specificityFormal NameAbbreviationOriginSubstrate specificityReferencesUDP-GalNAc:polypeptide N-acetylgalactosaminyl transferase IppGalNAc-T1humanSer/ThrWhite, T. etc (1995)UDP-GalNAc:polypeptide N-acetylgalactosaminyl transferase IIppGalNAc-T2humanSer/ThrWhite, T. etc (1995)UDP-GalNAc:polypeptide N-acetylgalactosaminyl transferase IIIppGalNAc-T3humanSer/ThrBennet, E. P. etc (1996)UDP-GalNAc:polypeptide N-acetylgalactosaminyl transferase IVppGalNAc-T4humanSer/ThrBennet, E. P. etc (1998)UDP-GalNAc:polypeptide N-acetylgalactosaminyl transferase VIppGalNAc-T6humanSer/ThrBennet, E. P. etc (1999) (1)UDP-GalNAc:polypeptide N-acetylgalactosaminyl transferase VIIppGalNAc-T7humanSer/ThrBennet, E. P. etc (1999) (2)UDP-GalNAc:polypeptide N-acetylgalactosaminyl transferase VIIIppGalNAc-T8humanSer/ThrWhite, K. E. etc (2000)UDP-GalNAc:polypeptide N-acetylgalactosaminyl transferase IXppGalNAc-T9humanSer/ThrToba, S. etc (2000)UDP-GalNAc:polypeptide N-acetylgalactosaminyl transferase XppGalNAc-T10humanSer/ThrJP No. 2001-401455 (unpublished)UDP-GalNAc:polypeptide N-acetylgalactosaminyl transferase XIppGalNAc-T11humanSer/ThrJP No. 2001-401507 (unpublished)UDP-GalNAc:polypeptide N-acetylgalactosaminyl transferase XIIppGalNAc-T12humanSer/ThrJP No. 2001-401507 (unpublished)UDP-GalNAc:polypeptide N-acetylgalactosaminyl transferase XIIIppGalNAc-T13humanSer/ThrJP No. 2001-401507 (unpublished)UDP-GalNAc:polypeptide N-acetylgalactosaminyl transferase XIVppGalNAc-T14humanSer/ThrGuo, J. M. etc (2002)UDP-GalNAc:polypeptide N-acetylgalactosaminyl transferase XVppGalNAc-T15humanSer/ThrJP No. 2001-401507 (unpublished)UDP-GalNAc:polypeptide N-acetylgalactosaminyl transferase XVIppGalNAc-T16humanSer/ThrJP No. 2001-401507 (unpublished)UDP-GalNAc:polypeptide N-acetylgalactosaminyl transferaseppGalNAc-T17humanSer/ThrJP No. 2001-401507 (unpublished)XVIIβ1,4-N-acetylglactosamine transferaseβ4GalNAcThumanGM3, GD3, LacCerNagata, Y. etc (1992)UDP-GalNAc:N-α1,3-N-acetylgalactosamine transferaseHist blood AhumanFucα1, 2Galβ1-RYamamoto, F. etc (1990)grouptransferaseUDP-GalNAc:globoside α1,3-N-acetylgalactosamine transferase IformalinhumanGalNAcβ1-3Galα1-Xu, H. etc (1999)glycolipid4Galβ1-3Glc-CersynthaseChondroitin sulfate N-acetylglactosamin transferase ICSGalNAc-T1humanGlcAJP No. 2002-129156 (unpublished)Chondroitin sulfate N-acetylglactosamin transferase IICSGalNAc-T2humanGlcAJP No. 2002-24202 (unpublished)